Hysterectomy (surgical removal of the uterus) is performed on approximately 600,000 women annually in the United States. Hysterectomy is often the therapeutic choice for the treatment of uterine cancer, adenomyosis, menorrhagia, prolapse, dysfunctional uterine bleeding (abnormal menstrual bleeding that has no discrete anatomic explanation such as a tumor or growth), and muscular tumors of the uterus, known as leimyoma or uterine fibroids.
However, hysterectomy is a drastic treatment, having many undesirable characteristics. Thus, any method which can approximate the therapeutic result of a hysterectomy without removing the uterus would be a significant improvement in this field. Newer treatment methods have been developed for some diseases which may spare these women a hysterectomy.
In 1995, it was demonstrated that uterine fibroids could be treated without hysterectomy using a non-surgical therapy, specifically comprising bilateral intraluminal occlusion of the uterine arteries (Ravina et al., “Arterial Embolization to Treat Uterine Myomata”, Lancet Sep. 9, 1995; Vol. 346; pp. 671-672, incorporated in its entirety herein). This technique is known as “uterine artery embolization”. In this technique, uterine arteries are accessed via a transvascular route from a common femoral artery into the left and right uterine arteries by means of an intravascular catheter and embolic material, such as small metallic coils, polyvinyl alchohol particulate and the like, is delivered through the catheter to the uterine arteries which quickly become occluded.
The uterus has a dual (or redundant) blood supply, the primary blood supply being from the bilateral uterine arteries, and the secondary blood supply from the bilateral ovarian arteries. Consequently, when both uterine arteries are occluded, i.e. bilateral vessel occlusion, the uterus and the fibroids contained within the uterus are both deprived of their blood supply. However, as demonstrated by Ravina et al., the ischemic effects on the fibroid is greater than the effect on the uterus. In most instances, the fibroid withers and ceases to cause clinical symptoms.
However, many physicians do not possess the training or equipment necessary to perform catheter-based uterine artery embolization under radiologic direction. Accordingly, there are substantially fewer uterine artery embolizations performed, worldwide, each year than hysterectomies for symptomatic uterine fibroids.
Recently, fibroid treatment procedures have been described wherein the uterine arteries are temporarily occluded by an intravaginal device which is non-invasively pressed against the patient's vaginal fornix and clamped or otherwise pressed against tissue bundle with the patient's uterine artery being within the bundle. Pressure on the tissue occludes the underlying uterine artery. While these procedures have shown much promise, in many situations the devices described to date do not always allow for accurate placement of the clamping surfaces.
What is needed, therefore, are devices and methods to detect blood vessels and blood flow in blood vessels, and devices and methods to occlude blood flow in blood vessels such as the uterine arteries that can be used by physicians with limited training and equipment.